Cadmium(II) complex formation with glutathione

摘要: Complex formation between heavy metal ions and glutathione (GSH) is considered as the initial step in many detoxification processes living organisms. In this study structure coordination cadmium(II) ion GSH were investigated aqueous solutions (pH 7.5 11.0) solid state, using a combination of spectroscopic techniques. The similarity Cd K-edge L(3)-edge X-ray absorption spectra compound [Cd(GS)(GSH)]ClO(4).3H(2)O, precipitating at pH 3.0, with previously studied cysteine {Cd(HCys)(2).H(2)O}(2).H(3)O(+).ClO(4) (-) corresponds to Cd(S-GS)(3)O (dominating) Cd(S-GS)(4) four-coordination within oligomeric complexes mean bond distances 2.51 +/- 0.02 A for Cd-S 2.24 0.04 Cd-O. For (C (Cd(II)) approximately 0.05 M) moderate excess (GSH)/C = 3.0-5.0), mix species consistent broad (113)Cd NMR resonances range 632-658 ppm. alkaline 11.0 C 2.0 or 3.0), two distinct peaks 322 674 ppm are obtained. first peak indicates six-coordinated mononuclear dinuclear CdS(2)N(2)(N/O)(2) CdSN(3)O(2) fast exchange, whereas second sites. At high ligand tetrathiolate complex, Cd(S-GS)(4), characterized by sharp delta((113)Cd) signal 677 ppm, predominates. average distance, obtained from spectra, varied narrow range, 2.49-2.53 A, all regardless geometry.